In the 10-year period 1982-1991 inclusive, 6 cases of neonatal herpes simplex were diagnosed at the Royal Women's Hospital, Melbourne (1 disseminated, 1 pneumonitis, 4 cutaneous [1 with central nervous system involvement]), resulting in an incidence of 1 in 11,000 livebirths for this population. Three cases were due to HSV 1 and 3 to HSV 2. In no case did the mother have a recent or past history of overt genital herpes infection. Two cases were acquired in utero, an uncommonly recognized form of infection. A favourable long-term outcome occurred in 2 of 4 cases in which diagnosis was prompt and antiviral therapy was instituted rapidly. Routine antenatal screening in the last trimester of pregnant women with a history of genital herpes before pregnancy is not advised, because the results have been shown to be unreliable in predicting viral shedding and hence the infants' risk of exposure to virus at delivery. A protocol for management of herpes in pregnancy is included.